Read what Wikipedia has to say about "making a federal case of it" when you rob a casino.:

http://en.wikipedia.org/wiki/Hobbs_Act

The law goes back to 1951, surprisingly.

The government will often use the depletion of assets theory to prove the jurisdictional element. Under this theory, interstate commerce is affected when an enterprise, which either is actively engaged in interstate commerce or customarily purchases items in interstate commerce, has its assets depleted through extortion, thereby curtailing the victim's potential as a purchaser of such goods.

The chips may have been purchased from a supplier in another state.

Seems to me to violate the spirit of the Constitution regarding states' rights, but it's frequently used to bring the FBI into an investigation.